Plug and receptacle construction



July 5, c NHLLER PLUG AND RECEPTACLE CONSTRUCTION Filed Dec. 21, 1945 2 Sheets-Sheet 1 INVENTOR CHE/577A MILLfR ATTORN EY PLUG AND RECEPTACLE CONSTRUCTI ON Filed Dec. 21, 1945 2 Sheets-Sheet 2 INVENTOR RQZ/ 7 CHR/s T/A/V MILL ER BY %.-/2 W ATTORNEY Patented July 5, 1949 2,475,.lid

PLUG AND RECEPTACLE CONSTRUCTION Christian Miller, Norwalk, Conn., assignor to Edwards and Company, Inc., Norwalk, .Conn., a corporation of New York Application December 21, 1945, Serial No. 636,481

16 Claims.

This invention relates to disconnectable plug and receptacle construction, particularly of the kind employed in hospital signalling systems wherein the patients push-button switch is connected to the signalling circuits by way of a plug that is connectable to and disconnectable from a receptacle or outlet which is usually installed in the wall of the room.

One of the objects of this invention is to provide a practical and reliable signalling plug and receptacle construction in which the signalling circuits are activated in response to disconnection of the plug from the receptacle and in which the restoration of the signalling circuits to inactive condition may be effected in a simple, practical, and dependable manner. Another object is to provide a plug and receptacle construction of the above-mentioned character in which change-over from inactive to active condition of the signalling circuits, and vice versa, can be effected in a foolproof manner and by structural features that will be compact in construction, capable of facility of assembly, and of long-lasting and dependable action. Another object is to provide a construction of the abovementioned character in which manual changeover of the condition of the signalling circuit can be effected in a simple way and by structural features that will make for ease and certainty of actuation or control by attendants who, therefore, need not be skilled in electrical complexities of the circuit arrangement or the like. Another object is to provide, in a construction of the above-mentioned character, simple, compact, and reliably-acting coacting mechanisms tionally improved plug and receptacle construction, and other objects will be in part obvious or in part pointed out hereinafter.

In the accompanying drawings, in which are shown several illustrative embodiments of my invention,

Fig. 1 is a plan View of the receptacle, with the plug removed;

Fig. 2 is a central vertical sectional view as seen along the line 2-2 of Fig. 1, and showing in side elevation and partly in central section the plug for coaction with the receptacle;

Fig, 3 is a transverse sectional View as seen along the line 3-3 of Fig. 2;

Fig. 4 is a view like that of Fig. 3 showing a modified form of construction of certain features;

Figs. 5 and 6 are elevations of short-circuiting elements employed respectively in the constructions of Figs. 3 and 4;

Fig. 7 is a transverse sectional view as seen along the line 'I! of Fig. 2;

Fig. 8 is a fragmentary vertical sectional View along the line 88 of Fi 1;

Fig. 9 is a fragmentary vertical sectional view as seen along the line 9-9 of Fig. 4;

Fig. 10 is a horizontal sectional view along the line Illof Fig. 2, certain parts being omitted;

Fig. 11 is a top plan view of a plug-actuatable device forming part of the receptacle construction as seen along the line ll-ll of Fig. 2; and

Fig. 12 is a bottom view of a part of the receptacle closing structure as seen along th line [2-42 of Fig. 2.

Similar reference characters refer to similar parts throughout the several views of the drawings,

Referring first to Fig. 2, the receptacle, generally indicated as a Whole by the reference character l5, preferably comprises two parts, a lower part is and an upper part ll, preferably made, as by molding, of an insulating material such as Bakelite; the lower part It is shaped to provide for the ready mounting thereon of the contact springs and connecting terminals therefor, and the upper part I1 is arranged to provide the necessary number of holes 18 (see Fig. 1), illustratively five in number, for the passage therethrough of the plug contacts IQ of the plug which is generally indicated by the reference character 29 in Fig. 2. A suitable disposition of the holes in the part I! is indicated in Fig. l, and the contacts [9 of the plug are similarly disposed for ready reception into and through the holes.

The plug contacts l9, when entered into the holes l8, are each to make electrical contact with a receptacle contact spring, thus to extend the circuits of the latter to the pushbutton switch (not shown) which is connected to the end of the flexible multiple conductor or cord 22 and which is constructed in known manner to eifect closure simultanteously of a number of signalling circuits, usually four in number where five plug contacts are employed, the fifth plug con tact and its associated receptacle contact spring being connected in a. return circuit common to the rest. Preferably the plug contacts and the receptacle contact springs are suitably constructed to effect mechanical interengagement so as to releasably hold the plug assembled to the receptacle l 5, and this I may effect by giving the upper end of each contact spring V-bends, as at 23, to become seated in a v groove 24 in the plug contacts IS, the extreme ends of the latter being rounded over as shown in Fig. 2 to facilitate camming of the V-bend 23 into and out of engagement with the V-groove 24 as the plug is assembled to or removed from the receptacle.

The five receptacle contact springs are preferably of identical construction, each comprising an elongated fiat spring 25 and a flat backing spring 28, both made of a suitable material such as Phosphor bronze or the like, and together they are carried by the lower receptacle part It to extend upwardly into appropriate relationship to the holes I 8 in the upper part H.

The lower part I6 is molded or shaped to have at its lower end a relatively heavy mounting part 27 and an upper flange part28, the parts 2! and 23 being joined by Vertically extending ribs R which are integrally formed with the parts 27 and 28 and are spaced about the central vertical axis of the receptacle structure substantially equiangularly as appears better from Figs. 3, 4, and '7, it being noted that, in horizontal cross-section, the ribs R. are V-shaped with their apexes directed inwardly toward the center and equiangularly spaced from each other (see Fig. 7). As better appears from Figs. 2 and 7, the inner portions of these ribs R extend upwardly from the upper face of the mounting part 21 and outer i portions thereof extend downwardly along the sides of the mounting part 21, the adjacent parallel faces (Fig. 7) forming, with the side faces of the mounting part 27, vertically extending external grooves in which the lower end portions of the overlying contact and backing-up springs 25, 26 are received and thereby aligned in appropriate upwardly extending directions, being secured in position by screws 30 which are threaded into the mounting part 21 and which also and similarly secure and align in downwardly projecting direction the heavy sheet-metal connecting lugs 3|, one for each contact spring and each provided at its lower end with suitable means such as a screw 32 for securing a conductor thereto.

The upper receptacle part I! comprises a flange part 34 which mates in face-to-face contact with the flange part 28 (Fig. 2), a side wall 35, and a top wall 36, the five holes l8 being provided in the latter. The holes I 8, and also the receptacle contact springs in the lower part [6, are spaced at sixty-degree intervals, thus leaving an interval considerably greater than sixty degrees, to the left as viewed in Fig. 1, for a purpose later described. Projecting downwardly from the top wall 36 of the upper part I! (Fig. 2 and integrally formed therewith and with the side wall are V-shaped ribs R (see also Fig. 12), one to each side of a hole 18 and each forming in effect, when the upper part I! is assembled to the lower part I6, upward extension of the ribs R formed in the lower part [6, the upper ends of the contact springs 25, 26 projecting upwardly between them, excepting at the abovementioned larger angular interval at the left, the bounding ribs R of which have their adjacent parallel faces 37 spaced farther apart to provide a wider rectangular recess 38 in the upper part H, for a purpose later described.

As indicated in Fig. 1, the side wall 35 of the upper part I? may be circular and the flange parts 34 and 28 may be square, thus providing corner at which the upper and lower parts It and I? may be secured together as by screws 48.

The parts are preferably so proportioned that the backing-up spring 26 can be straight, as shown in Fig. 2, while the contact spring 25, hav-- ing the above-described V-shaped end 23, has a lower end portion 4| which rests against the side face of the mounting part 21, underneath the straight backing-up spring 26, whence it is bent inwardly so that its upper portions normally as" suine a position spaced inwardly from the upper end of the backing-up spring 26, thus bringing the upper portion of the V-bend 23 of each contact spring more or less in line with the center of the hole l8 which it underlies. At an intermediate point each contact spring 25 has a camshaped knee or V-bend 42. With the plug removed and hence with the upper ends of the contact springs 25 unrestrained by the plug contacts, the spring contacts 25 move radially inwardly under their own spring action. With the plug inserted, the camming action of the plug contacts E9 cam the'springs radially outwardly to permit entry of the plug contacts, whence the inherent bias of the contact springs 25 enters their V- bends 23 into the V-groove 24 of the plug contacts, thus making good electrical connection with the latter and forming a releasable mechanical interlock.

The above-described radial inward movement of the several contact springs 25 in the receptacle, when the plug 20 is removed, is utilized to effect an activation of the signalling circuits the same as is effected by actuation of the push-button switch at the end of the multiple conductor cord 22 above mentioned, and this is effected by means of a conductive plate P, provided with portions that are in the path of radial inward movement of the contact springs 25, thus effecting electrical connection or short-circuiting between the above-mentioned four signalling circuits and the common or return line thereof, and thereb actuating the several signals. The plate P is preferably constructed to be held in assembled position and in proper relationship to the several contact springs 25 by the assemblage together of the upper and lower parts It and I7, and for this purpose I prefer to make use of the ribs R in the lower part l6 and the ribs R in the upper part ll, appropriately shaping their adjacent ends to receive the plate P between them, and this arrangement I may vary according to the shape that it is desired to give to the conductive plate P.

For example, the plate may take the form indicated at 44 in Fig. 5, being in the form of a heavy sheet-metal stampin that is hexagonal in outline, excepting that in one edge face it there-- of it is cut away to provide a recess 44*, the width of which substantially matches that of the recess 38 in the upper part I! (see Fig. 12), leaving five edge contact faces F, one for each contact spring 25. As is better shown in Fig. 3, each of the ribs R of the lower part l6 is cut away or molded at its upper end, to 'adepth substantially equal to the thickness of the conductive plate 45 to provide seats S which, moreover, are shaped with angular outer walls in which the apexes formed by adjacent faces F--F are received, thus preventing rotary movement of the plate 44 and also holding it against transverse shift and thus maintaining it coaxial with the receptacle construction. This relationship of the parts also insures that the recess 44' in the plate 44 is held aligned with the recess 38 in the upper part 11, the plate 44 overlying the ribs R, also stepped, that underlie the two ribs R that are to either side of the recess 58 in the upper part ll. When the latter is assembled to the lower part t6, the plate 44 of Figs. 3 and 5 is thus held in its seats in the lower ribs R by the ends of the overlying ribs R of the upper part 117.

The plate P of Fig. 2 may, however, also be made in the form of a disk 45 shown in Figs. 4 and 6, being cut away as at 45 to provide a recess like the recess 44 of the plate 44 of Figs. 3 and 5. In such case the seats S (Fig. 4) formed in the ribs R need not be angular at their outer walls but can be of the same curvature as the periphery of the plate 45, and to prevent rotary displacement of the slot or recess 45', one of the ribs R is formed without a seat S and at a corresponding point in the disk-like plate 45 the latter has formed in it a V-shaped notch 45 in which is accommodated the upper end of the just-mentioned rib R that has no seat formed in it, as is shown in Fig. 9. The ribs R of the upper part 11, however, overlie those portions of the plate 45 that rest against the stepped or seated ribs R and hence the plate 45 is held against axial displacement.

If the depth of the seats formed in the ribs just matches the thickness of the plate, the latter is also held against axial movement and the parts may even be so proportioned as to effect some measure of clamping of the plate 44 or 45 when the screws 45 draw the upper and lower parts it and IT into final assembled relation. It may, however, be desirable to allow some play or movement in a vertical or axial direction in order to achieve some greater measure of wiping action between the contact springs 25 and the conductive plate, and in such case the seats in the lower rib B may be made of greater depth, as is indicated in Fig. 8.

The plate P, whether it takes the form shown at 44 in Fig. 5 or at 45 in Fig. 6, is provided with a central hole 48 which is coaxial with a central bore 49 that extends through the mounting part 27 of the lower receptacle part [5 (see Fig. 2), the bore 45 forming a sliding bearing for the lower end of a round stem 50 that extends upwardly through the hole 48 in the conductive plate P, being thereby also guided for vertical movement. Intermediate of its ends the stem 50 carries a cam 5! which may be molded out of insulating material such as Bakelite, constructed to coact with the ends or V-bends 42 in the contact springs 25. About the lower end of the stem 50 is a coiled compression spring 52, the upper end of which abuts against the under side of the cam 5| and the lower portion of which extends into a counterbore or recess 45 that is coaxial with the bearing recess 49. Spring 52 normally holds the cam 54 and hence the stem 50 in uppermost position, that being determined by the conductive plate P which is held in between the two parts I6 and I1 and against the under side of which the upper face of the cam 5| abuts; in this position of the stem 55 and cam 5|, the upper end of the stem 55 projects a substantial amount beyond the top wall 35 of the upper part I! so that it may be manually actuated downwardly against the action of the spring 52.

With the cam 5! in uppermost position, the plane of its under face is somewhat above the apex of the V-bends 42 of the contact springs 25 so that the latter are free, under their spring action, to move radially inwardly as above described to contact the plate P when the plug is removed, thus setting all of the signals. The side face of the cam 5i has a lower band-like cylindrical part 5W which is of substantially the same radius as the circle upon which the apexes of the ribs R lie, so that the part 5| and the ribs R may coact and guide the earn 5! in its movements. Above the part 5W the cam 5! has a frusto-conical cam surface 5| the two cam surfaces coacting with the v-bends 42 of the contact springs, both when the stem 50 is depressed and when it is released for upward movement, as is later described.

When the stem 50 is depressed, the lower edge of the cam part 51 engages the upper cam face of the V-bends 42, camming the latter and hence the contact springs 25 radially outwardly to disengage them from the plate P, that action being continued when the frusto-conical cam face 5| engages the knees 42, completing the radial outward movement of the five contact springs 25 and, by the tension thus placed in the springs 25 and now also in the backing-up spring 26, causing the radial inward pressure exerted by the knees 42 on the cam face 5! to be resolved into a vertical component tending to force the cam 5| and the stem 55 upwardly, aided by the now additionally compressed spring 52, and, unless the cam 51 is held in its position displaced downwardly from the fixed plate P, it and the stem 50 would snap upwardly and restore to a position as limited by the fixed plate P.

However, by the time the above-described downward movement of the cam 5| is completed, a stop member 53 rides into the path of upward movement of the cam 51 and prevents it from partaking of such upward movement. Cam 5| is thus held in downward position and contact springs 25 prevented from engaging the plate P.

The stop member 53 is in the form of a downwardly-projecting stud-like part of a horizontal lever 54 which, as is better shown in Fig. .11, is provided with spaced ears 55 receivable between spaced ears 55 formed at the upper end of a fiat post 57, a pin 58 passing through holes in these cars and thus forming a pivotal connection for the lever 54 and the stud 53. About the pin 58 is a coiled spring 56, the respective ends of which abut against the post 51 and the stop stud 53, acting upon the latter to tend to swing it in counter-clockwise direction as viewed in Fig. 2. The greater width (vertical dimension as seen in Fig. 11) of these parts is accommodated in the wider recess 38 in the upper part I! above described, the fiat post 57 extending downwardly in the narrower space between two of the ribs R of the lower part it where it is secured by screws 5! to the mounting part 2?, much in the same manner as the contact springs 25, 26 are secured by the screws 35 as above described.

The stop arm or stud 53, which may be of sheet metal and formed up out of the sheet metal of the lever 54, extends downwardly through the plane of the conductive plate P by way of the cut-out or recess 44* in Fig. 5 or 45 in Fig. 6, and in the position of the parts as shown in Fig. 2, it is pressed by the spring 60 against a vertical fiat face 51 (see also Fig. 10) formed at a side of the cam 5! but positioned at a greater radius th 11 ott m th ce s nt h condu tive plate,"s'o that upon downward'movementfof the cam to a sufficientextent' see Fig.-'2'), the 'stud 53 can ride in counter-clockwise direction overthe upper face of thecarnfil toan-extent limited bythe left-hand edge face of the'plate' P formed in the bottom of the recess M of Fig.

'5 or 45? of Fig. 6. The amount of inward or counter-clockwise swing of the stud 53 need not be more than the thickness of thestud'53j itself,

'soas' to require but a small clockwise swing'of jthe stud 53* to snaps into stopping position when thej 'lgne'es or V-fbends 42 ofthe springs 25 are engage frusto conical cam face 51'' of the cam: 5l, ;and the parts are dependably held in, this position by the upward stress exerted by the lznees '42 upon the cam 51 and also by that ofthe spring'52.

with the ,plate 1?. The reinsertion of the plug Tsrri {event of removal of the plug 20 to change over 2Q isfthus'achievedwithout activating the sig- "gfg'zircuits. With the restoration of the cam jnd stembll to uppermost position, the contact rigsjZBjniayagain engage the plate P in the t'h e' signalling" circuits to activated condition, a

conditionjwhichcan be undone by now manually 'fdepressingjhe stem 50, as above described, to

" brln'gthestop member 53 again into coaction with f glsisjbettershown in Fig. 10, I preferto form 15 by the i in'fthe c'a m L5! verticallyextending V-slots 10, one for each of the V-shaped ribs R in the lower part I B the coaction between these parts notpnly aiding and guiding the cam 5! in its vertical movements, but also in preventing it from'rotating" softhat the fiatside face 5| of the cam is "alwayspresented for coaction with the stop mem- The lever 55 (Figs. 2 and 11) is preferably-- shaped to provide a hole 62 materially larger than the upper part of stem 50 so as not'to bind with the latter in course of any tilting movement of the lever 54 itself, and thus it provides an'annular fbe'r 53. S1lOl,l1d' the short-circuiting plate be mounted to havesome leeway of vertical moveinent, as was above' described in connection with "Fig. 8, such movement is preferably very slight, "being insuiiiclent to change the relationship beor ring-shaped part 63 that surrounds the stem- 56 underneath and spaced downwardly from the top wall 35 of the upper part ll, being engaged by the convex annular under-face 6410f a'collar 65 that extends relatively loosely about the upper tween the plate and the contact springs but being sufficient topermit more rubbing movenent' to take place between the two than occurs under the bias of thesprings 25 themselves, thus end of the stem Elland is slldably guided in aholelifi in the top wall 36, a peripheral flange65 of'the collar 85' being engageable' with the under side of the top wall 36 to limit theextent to which the collar 85 projects upwardly beyond thetop wall36. ,The angle between the lever 54 and the 7 stop 53 is suchthat, with the stop part 53 engaging the flat side face 51 of the cam 5|, the lever 54, through its annular part '63, holds the collar 65 in upward position with some leeway for slight additional upward movement when the parts swing a bit more in counter-clockwise direction as the stop part 53 rides inwardly onto the upper face of the cam 5 l.

With the cam 5! held by the stop 53, in desired position, in response to downward actuation of the stem 59 manually to inactivate the signals that are set when the plug is removed from the receptacle, the parts remain in'these positions and the signals remain unactivated until the plug team in keeping the contacting surfaces clean and bright and hence of low resistance.

It will thus be seen that there has been provided in this "invention a plug and receptacle construction in which the several objects above noted, togetherivith many thoroughly practical advantages, are successfully achieved. It will be "seen that the'stru ctu'r'e is compact and is of thorbughly dependable action and, moreover, is capable'of speed and facile assembly, many of the parts, when assembled in appropriate sequence, being brought into the entity for proper structuralandfunctional coaction merely by the securing" together of the upper and lower parts of thereceptacle'itself; I

' 'As many' possible embodiments may be made of 'the "above invention and as many changes might b'e'madein the embodiment above set forth,

20 is reinserted or is reassembled to the receptacle 15. As shownin Fig. 2, the pIugZIL'made'or molded out of any insulating material like Bakelite, has at its center a stepped or counter-bored recess 68 of a depth and diameteradequately it"is to be'understood that all matter hereinbefore set forth or shown in the accompanying drawing is to be interpreted as illustrative and no'tin' a limiting sense;

claim? l 1.;Aplug and receptacle construction comprising a receptaclebody of insulating material and a plug body of insulating material, the plug body toaccommodate the stem when the latter 'is in its uppermost position, the step or shoulder in the recess 68 taking over the outwardly-pro jecting collarfib and engaging it during the latter portion of the movement necessary to complete the assemblage of the plug 20 to the receptacle l5* and hence forcing it downwardly, thereb'y'depressing the lever 54 and swinging the stop part 53 laterally out of engagement with the top'surface of the cam 5|, whence the upward reaction having'a-plurality of plug contacts and the receptaclebody having a plurality of recesses both grouped aboutthe common axis of the two bodies .for the reception of the'plug contacts into the receptacle "recesses, said receptacle body comprising two parts with means securingthem together along substantially a transverse section of the receptacle body, a conductive plate within of the knees 42 on the cam surface '5l aided by said receptacle body and extending transversely thereof and received between and held in position by said two body parts, said receptacle body having a"plurality of contact springs respectively :fexposed in said recesses for engagement respectifvelfy by'f said plug contacts and biased inwardly "for engagement 'with said conductive plate, said 'plugfcontactsholding said spring contacts out of engagement-with said plate, cam means having means mo'untingit for movement within said recigitaclebo'dy and 'along' the axis thereof and a apted upon actuationin one direction to bias said r ng-gunners1m a direction away from said conductive plate and upon actuation in reverse direction to permit movement of the spring contacts in a direction toward said conductive plate, means projecting from said receptacle body and along the axis thereof and toward said plug body for actuating said cam means in said first direction, said plug body having recess means for accommodating said projecting means, means for holding said cam means upon actuation in said first direction, and movable means projecting from said receptacle body and engageable by said plug body on assembly of the latter to the receptacle body for releasing said holding means.

2. A plug and receptacle construction comprising a receptacle body of insulating material and a plug body of insulating material, the plug body having a plurality of plug contacts and the receptacle body having a plurality of recesses both grouped about the common axis of the two bodies for the reception of the plug contacts into the receptacle recesses, said receptacle body comprising two parts with means securing them together along substantially a transverse section of the receptacle body, a conductive plate within said receptacle body and extending transversely thereof and received between and held in position by said two body parts, said receptacle body having a plurality of contact springs respectively exposed in said recesses for engagement respectively by said plug contacts and biased inwardly for engagement with said conductive plate, said plug contacts holding said spring contacts out of engagement with said plate, spring-opposed cam means within said receptacle body having means mounting it for movement in opposition to its spring to cam said spring contacts away from said conductive plate, means for holding said cam means in opposition to its spring in a position to hold said spring contacts away from said conductive plate, and movable means projecting from said receptacle body and movable by said plug body on assembly of the latter to the receptacle body for releasing said holding means.

3. A plug and receptacle construction comprising a receptacle body of insulating material and a plug body of insulating material, the plug body having a plurality of plug contacts and the receptacle body having a plurality of recesses both grouped about the common axis of the two bodies for the reception of the plug contacts into the receptacle recesses, said receptacle body comprising two parts with means securing them together along substantially a transverse section of the receptacle body, a conductive plate within said receptacle body and extending transversely thereof and received between and held in position by said two body parts, said receptacle body having a plurality of contact springs respectively exposed in said recesses for engagement respectively by said plug contacts and biased inwardly for engagement with said conductive plate, said plug contacts holding said spring contacts out of engagement with said plate, a member positioned at the axis of said receptacle body and projecting therefrom toward said plug body and having means responsive to inward axial movement thereof to disengage said spring contacts from said conductive plate, said plug body having a recess therein for accommodating said member when in projected position, and means responsive to inward movement of said member for holding it in inward position to thereby hold said spring contacts disengaged from said conductive plate and including a coaxial member concentrically arranged about said first member and projectible 10 toward said plug body in response to actuation of said holding means whereby said concentric member is engageable by said plug body on assembly of the latter to the receptacle body to move it inwardly of the latter and actuate said holding means into releasing position.

4. A plug and receptacle construction comprising a receptacle body of insulating material and a plug body of insulating material, the plug body having a plurality of plug contacts and a central recessed portion and the receptacle body having a plurality of recesses both grouped about the common axis of the two bodies for the reception of the plug contacts into the receptacle recesses, said receptacle body comprising two parts with means securing them together along substantially a transverse section of the receptacle body, a conductive plate within said receptacle body and extending transversely thereof and received between and held in position by said two body parts, said receptacle body having a plurality of contact springs respectively exposed in said recesses for engagement respectively by said plug contacts and biased inwardly for engagement with said conductive plate, said plug contacts holding said spring contacts out of engagement with said plate, movable means extending axially of the receptacle body and having a portion projecting from said receptacle body and adapted to be received in and shielded by the said recess in said plug body, and coacting upon movement in one direction to disengage said spring contacts from said conductive plate holding means movable into the return path of said movable means in response to said movement to hold said movable means against retrograde movement, spring means adapted to give said movable means retrograde movement when released from said holding means, and means responsive to movement on assembly of said plug body to said receptacle body for actuating said holdin means to release said movable means.

5. A plug and receptacle construction as claimed in claim 4 in which said spring means comprises a separate spring contained within, and disposed axially of the receptacle body, that is stressed in response to movement of said movable means in said one direction.

6. A plug and receptacle construction as claimed'in claim 4 in which portions of at least one of said two body parts, at said transverse section, are recessed to form a seat for said conductive plate, juxtaposed surfaces on said two parts holding said conductive plate against material movement.

7. A plug and receptacle construction as claimed in claim 4 provided with recess means of greater depth than the thickness of said conductive plate for receiving the latter, juxtaposed surface portions of said two parts overlying the respective sides of said plate to form said recess means whereby said conductive plate can partakeof a small movement to rub said contact springs during its engagement therewith.

8. A plug and receptacle construction as claimed in claim 4 in which said recesses are formed by the spaces between substantially mating rib elements in both parts of said receptacle body, at least certain of said rib elements having seats at said transverse section for receiving and holding said conductive plate.

9. A plug and receptacle construction as claimed in claim 4 in which said recesses are formed by the spaces between substantially mating rib elements in both parts of said receptacle certain of said recesses" for receiving said plug contacts, said spring contacts extending upwardly within said certain spaces. and into the upper ends thereof, and means for. mounting said contacts at their lower ends to saidfreceptacle body, said holding means, being mounted in one: of said spaces.

11. A plug and receptacle construction as claimed in claim 4 in which: the part of said re.- ceptacle body remote from said plugbody comprises a mounting partlhaving upstanding 'there-' from a plurality of rib elements'to form vertically-extending spaces therebetween,.at least one for each of said plug-contact-receiving recesses, said spaces having received-therein.saidtcontact springs, and means securing the latter tosaid mounting part.

12. A plug and receptacle construction comprising a receptacle bodyv andva plug body,.the

plug body having a plurality ofplug contacts and.

the receptacle body comprising two parts with means securing them togetherralong substantially a transverse sectionof thesreceptaclebody, the.

part adjacent the plug body having recesses therein for respectively receiVingJsaid plug contacts, the other part of .said receptacle body comprising a mounting part and a:plurality of upstanding spacedrib elements grouped about said common axis and providing 'a'. plurality ofspaces each terminating in juxtaposition to one of said recesses, a plurality of contact springs received in said spaces with means securing their lower ends to said mounting part for coa'ction at their upper ends respectively with said plug'contacts, a relatively fixed conductive means carried by said receptacle body and engageable by said spring contacts upon disengagement of the latter by sa d plug contacts,-and means extending and movable along the axis ofsaidtwo' receptacle body parts and projecting from one of 'them toward said plug body, said last-mentioned'means having means for actuating said spring contactsout of engagement with saidconductive'means.

13. A plug and receptacle-construction comprising a receptacle body and aplug body, the

plug body having a plurality of plug contacts and the receptacle body comprising two parts with means securingthemtogether along substantially a transverse section ofthe receptacle body, the part adjacent the plug body having recesses therein for respectively receiving said plug contacts, the other-part of said receptacle body comprising a mounting 'part'and a plurality of upstanding spaced rib elements grouped about said common axis and'providinga plurality of spaces each terminating in-juxtaposition toone of said recesses, a plurality of contact springs received in said spaces-with means'securingjtheir lower ends to said mounting part for coaction at their upper ends respectively with said plug contacts, a relatively fixed 'conductive'means carried by said receptaclev body-and engageable by said spring contacts upon'disengagement of the latter by said plug contacts, saidreceptacle body part that is adjacent the plug bodyhavingga coaxial aperture, means movable axially within said receptacle body for disengaging, said? contact. springs from said conductivemeans, andmeans' projecting through said aperture'and engageable: and movable by said plug bodyupon assembly of the latter to the receptaclebody for-effectingmovement of said movable means: in a direction to permit said spring, contacts-to move inzdirec tions to engage said conductivemeans.

14. A plug and receptacle COIIStIHCtlOIIYCOIIIe prising a receptacle body of insulatingmaterial and a plug body of insulating; material, the plug' body having a plurality of plug contacts and the receptacle body having a plurality ofirecesses both grouped aboutrthe common axis of T the two bodies for the reception of the 'plug contacts into the receptacle recesses, said receptacl'e'b'odyl'comeprising two parts with means securingthem to-' gether along substantially a transverse section'ofi' the receptacle body, a conductive plat'ewithin said receptacle body and extending transversely thereof and received between and held in position by said two body parts, said receptacle body" having a plurality of contact springs respectively exposed in said recesses for engagement-respectively by said plug contacts and biased-inwardly for engagement with said conductive plate, said plug contacts holding said spring contacts out of engagement with said plate, and movable means coacting upon movement in one directi'onto dis' engage said spring contacts from said conductive plate, one or more of said spring-contacts comprising a cam-like portion operative under the spring bias of said spring contacts-to cam said movable means in retrograde direction.

15. A plug and receptacle construction com'-- prising, a receptacle body, and a plug body, the receptacle body having a plurality of recesses therein and said plug body having a plurality of contacts adapted to be inserted in said recesses respectively, a circuit closing plate disposed substantially at right angles to the axis of-said re-- ceptacle body, said receptacle body having a plurality of contact springs disposed for engagementrespectively by said plug contacts when they are inserted in said recesses, and biased inwardly for engagement with said circuit closingplate when said plug contacts are not inserted in said reesses, said plug contacts wheninserted holding said spring contacts out of engagement with said prising, a receptacle body, and a'plug body, thereceptacle body having a plurality of recesses therein and said plug body havinga-plurality of contacts adapted to be inserted in said recesses respectively, a circuit closing plate disposed substantially at right angles to the axis of said receptacle body, said receptacle body having a plurality of contact springs disposed for engagement respectively by said plug contacts when they areinserted in said recesses, and biasediinwardly for engagement with said circuit closingqplate when" said plug contacts are not inserted" in said recesses, said plug contacts when inserted holding said spring contacts out of engagement with said plate, a'circuit opening plunger'assembly; disposed axially of said receptacle body. andplug,

which, when moved in one direction, will move said spring contacts away from said plate, and

13 means resisting such movement for returning said circuit opening assembly to its original inoperative position, means for locking said assembly in circuit opening position, and means actuated by engagement of the plug body in said. receptacle body for releasing said assembly locking means.

CHRISTIAN MILLER.

REFERENCES CITED The following referemces are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Kenerson May 30, 1933 Auth Feb. 25, 1936 Curtiss Apr. 22, 1941 Crockett Aug. 13, 1946 

